1. Field of the Invention
The present invention relates to the field of accessing data of a cloud database, and more particularly to a system for accessing data of a cloud database via transparent technology, wherein after data of a Transmission Control Protocol/Internet Protocol (TCP/IP) format are converted into data of a Hyper Text Transmission Protocol (HTTP) format, the data are transmitted to a server through a channel, and then the HTTP format is converted back to the TCP/IP format before the data are transmitted to a cloud database end in order to break through the blocking of a firewall and transmit the data successfully.
2. Description of the Related Art
Open Data Base Connectivity (ODBC) built on the client-server architecture provides a standard Application Programming Interface (API) for transmitting a Structured Query Language (SQL) instruction to access data from a remote-end database through a network layer. The ODBC creates the possibility of using an open database, and the architecture of the ODBC is mainly divided into four units, respectively: application, driver manager, driver and data source. The application externally provides users a talking interface, and internally executes a data preparation, calls an ODBC program function, transmits a SQL instruction, and receives and displays results returned from the database. The driver manager and the driver are dynamic link library (dll) files, and the driver manager assists the application to load the source driver and connect to the data source, and the driver is mainly provided for executing a relative ODBC function and communicating with the corresponding data source. When the application calls an ODBC function such as SQLConnect or SQLDriverConnect, the driver manager will load the relative driver and call the application, so that the application can complete the connection by a corresponding driver without the need of considering the type of data source.
Obviously, the ODBC creates the independent characteristic between the application and the database. However, in the aforementioned client-server architecture, the application requires maintaining an uninterruptable smooth connection before Commit, Rollback or Timeout completes. Now, if the database is hidden behind a firewall for the purpose of network security, the application will be unable to use the original driver directly to connect the database, but it will use a VB6 or a PHP language to edit the program code of the driver and the function installed in the driver manager, and further use the TCP/IP architecture to build another communication channel before breaking through the firewall to complete the connection, and thus causing difficulties and inconvenience to the application. In addition, if the database is a cloud system, then the level of complexity of editing the program code and the function will become higher, and thus affecting the quality of accessing data of the database.
To overcome the aforementioned problem, it is a main subject of the present invention to create an additional channel by using the present common HTTP tunneling to break through the firewall of the network, so as to connect to a cloud database behind a firewall without modifying that the program code and function of the application.